1. Field of the Invention
This invention relates to adjustable lighters which consume fuels, such as butane, by converting them to a gaseous state and burning them. More particularly, the invention relates to a novel apparatus for controlling the range through which the fuel consumption rate may be adjusted.
2. Description of the Prior Art
Various prior art lighters, some of them including means for varying the height of the flame produced by the lighter by controlling the rate at which fuel is consumed, and some of them further including means for limiting the range through which the flame may be adjusted, are known. However, these devices also have a number of known deficiencies which limit their use. Many of the mechanisms are relatively complicated and therefore suffer from the twin disabilities of a high manufacturing cost as well as a relatively high likelihood of mechanical failure during use. Another disadvantage of some of these devices is the fact that the particular construction limits the shape of the lighter housing due to the fact that the housing must be large enough to accommodate the adjustment mechanism.
Still another major deficiency of present day devices pertains particularly to their attempts at controlling the flame heights within pre-selected ranges. In the absence of a positive reliable means for controlling the flame height range -- particularly the maximum flame height -- these lighters present an ever existing hazzard to consumers who may suffer skin burns caused by a flame having an unexpected excessive height.
A typical adjustable lighter is disclosed in U. S. Pat. No. 3,280,599 to Projahn. In this patent the height of the flame is varied by rotating an adjustment screw which is coupled to a rotary valve. The rotation of the valve is limited by a toothed element, only a portion of which has teeth cut into it. The toothed element is secured to the adjustment screw and held in position by friction. The toothed element is in turn coupled to a gear which is mounted for rotation adjacent the valve adjustment screw. Due to the fact that only a portion of the toothed element contains teeth, the valve adjustment screw which is coupled to the toothed element is only free to rotate through angular positions in which the teeth of the toothed element are in contact with the teeth of the gear. Thus while the motion of the adjustment screw is limited to a certain range, this device nevertheless suffers from several disadvantages. In order to permit the setting of a general range, the coupling between the toothed element and the adjustment screw is one which will slip when a minimum magnitude of force is applied. Thus, it is likely that with wear or with time or simply with excesssive force, the size of the flame may vary out of the desired range, causing several problems. For example, if the valve setting is too low, the lighter will not ignite. Likewise, if the valve setting is too high, a user actuating the lighter while it is next to his face is likely to be injured by an excessively large flame.
An alternative method of limiting the angular displacement of the adjustment screw on the lighter is disclosed in U. S. Pat. No. 3,213,648 to Racek. In this patent the desired adjustment range limitation is achieved by providing a stop hump on the top of the lighter and providing a toothed disk which has had one of its teeth bent into the path of the stop to serve as a co-operating stop. This device has a number of disabilities which limit its usefulness. If the toothed disk is to properly serve its additional function of an operating knob, it must have a minimum physical strength. If it has this minimum physical strength, it then becomes relatively difficult to bend the tooth. If on the other hand, the disk is made with a bent tooth, it is not possible to select a tooth and thus select a given range. Still another disadvantage is that some modification of existing equipment must be made in order to manufacture a case having the desired stop hump.
U. S. Pat. Nos. 3,208,244 to Mandy and 3,161,034 to Meyers both include constructions where the desired range limiting function is done by a combination which includes an inner toothed wheel, an outer washer which has teeth along its inner circumference which mate with the teeth of the inner wheel and special range limiting structure. This structure is relatively expensive to manufacture and includes the further disadvantage of requiring a rather specialized lighter construction in order to accommodate the range limiting mechanism. The lighters disclosed in these patents therefore cannot be made with conventional manufacturing equipment without major retooling and its attendant additional expense.
Still another lighter design which includes a limiting structure is disclosed in Japanese Pat No. 3,248,906 to Tomojiro Zaima. This design includes an adjustable finger wheel which includes a stopper for limiting rotary movement. However, the nature of this limiting structure is such that control of the range through which the lighter may be adjusted is relatively difficult.
The following patents also relate to lighters using butane fuel and the like
U. S. Pat. No. 3,184,931 to Zenzaburo Yoshino
U.S. Pat. No. 3,251,202 to A. Racek
U.S. Pat. No. 3,263,456 to L. S. Dexter
U.S. Pat. No. 3,314,252 to Yoshio Kanamaru
U.S. Pat. No. 3,382,028 to Sadao Yoshinaga
U.S. Pat. No 3,402,963 to L. S. Dexter
U.S. Pat. No. 3,414,364 to A. Bert
U.S. Pat. No. 3,423,160 to J. Genoud
U.S. Pat. No. 3,447,882 to S. H. Newman
U.S. Pat. No. 3,589,851 to Peter Rabe
U.S. Pat. No. 3,597,140 to Peter Rabe
U.S. Pat. No. 3,854,862 to M. E. Webster
While these patents relate to various developments in such devices, none of them relate to a lighter having the novel construction and safe, reliable flame height control such as I have invented.